The Monday 03 Mar 2014 à 16:28:48 (+0100), Max Reitz wrote :
> Implement this function in the same way as raw_bsd does: Acknowledge
> that this is a passthrough driver (always return BDRV_BLOCK_OFFSET_VALID
> and BDRV_BLOCK_DATA and derive the offset directly from the sector
> index) and add BDRV_BLOCK_RAW to the returned value.
>
> Signed-off-by: Max Reitz <mre...@redhat.com>
> ---
> block/json.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/block/json.c b/block/json.c
> index a2f4691..7392802 100644
> --- a/block/json.c
> +++ b/block/json.c
> @@ -113,6 +113,14 @@ static coroutine_fn int
> json_co_write_zeroes(BlockDriverState *bs,
> return bdrv_co_write_zeroes(bs, sector_num, nb_sectors, flags);
> }
>
> +static coroutine_fn int64_t json_co_get_block_status(BlockDriverState *bs,
> + int64_t sector_num,
> + int nb_sectors, int
> *pnum)
> +{
> + return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID | BDRV_BLOCK_DATA |
> + (sector_num << BDRV_SECTOR_BITS);
> +}
I don't understand what is the selling point of this method instead of calling
bdrv_co_get_block_status on bs->file.
Some information risk to be lost and it does look like magic.
Best regards
Benoît
> +
> static void json_invalidate_cache(BlockDriverState *bs)
> {
> return bdrv_invalidate_cache(bs->file);
> @@ -159,6 +167,7 @@ static BlockDriver bdrv_json = {
> .bdrv_aio_discard = json_aio_discard,
>
> .bdrv_co_write_zeroes = json_co_write_zeroes,
> + .bdrv_co_get_block_status = json_co_get_block_status,
>
> .bdrv_invalidate_cache = json_invalidate_cache,
>
> --
> 1.9.0
>
>
